Evaluating the Combined Effect of Oral Premedications on Inferior Alveolar Nerve Block Effectiveness

Detailed Description of the Study Title Evaluation of Combined Effect of Oral Premedication on Enhancing the Effectiveness of Inferior Alveolar Nerve Block in Mandibular Teeth with Symptomatic Irreversible Pulpitis

Background and Rationale Achieving effective local anesthesia is a cornerstone of pain-free endodontic treatment. The inferior alveolar nerve block (IANB) is commonly used to anesthetize mandibular teeth. However, its success rate significantly drops in cases of symptomatic irreversible pulpitis, primarily due to inflammatory changes, nerve sensitization, and increased prostaglandin production. Prostaglandins, synthesized via the cyclooxygenase (COX-1 and COX-2) pathway, lower the pain threshold and reduce anesthetic efficacy.

Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen are widely used to reduce inflammation by inhibiting COX enzymes, thereby decreasing prostaglandin production. Several studies have shown that preoperative ibuprofen can enhance the effectiveness of IANB. However, other studies report conflicting results.

On the other hand, serratiopeptidase is a proteolytic enzyme known for its anti-inflammatory, mucolytic, fibrinolytic, and analgesic properties. It also acts on the COX pathway and reduces prostaglandin levels, offering a potentially synergistic effect with NSAIDs.

This study aims to evaluate the combined effect of ibuprofen and serratiopeptidase as premedication on improving the effectiveness of IANB in mandibular teeth with symptomatic irreversible pulpitis. To date, no published research has explored the combined preoperative use of these two agents for this purpose.

Objective To evaluate whether combined oral premedication with ibuprofen and serratiopeptidase enhances the anesthetic effectiveness of inferior alveolar nerve block in mandibular teeth diagnosed with symptomatic irreversible pulpitis, compared to individual or no premedication.

Research Question Does the combined oral premedication of ibuprofen and serratiopeptidase improve the success rate of IANB more than when either drug is used alone or a placebo is given?

Hypothesis Null Hypothesis (H₀): Combined oral premedication with ibuprofen and serratiopeptidase has no significant effect on the effectiveness of IANB.

Alternative Hypothesis (H₁): Combined oral premedication with ibuprofen and serratiopeptidase enhances the effectiveness of IANB.

Study Design A prospective, randomized, controlled clinical trial using non-probability consecutive sampling.

Study Setting and Duration Conducted in the Department of Operative Dentistry & Endodontics, Dental College HITEC-IMS, Taxila, over a period of 6 months following ethical and institutional approval.

Sample Size A total of 96 patients will be enrolled (24 patients per group), calculated using 80% study power, a 5% level of significance, and expected success rates of ibuprofen (78%) and serratiopeptidase (76.3%).

Eligibility Criteria

Inclusion criteria

Age between 18-45 years

Mandibular molars or premolars with deep carious lesions

Clinical diagnosis of symptomatic irreversible pulpitis

Normal periodontal ligament (PDL) space on IOPA

No analgesics taken within 12 hours of treatment

Exclusion criteria

Presence of periapical radiolucency

Teeth tender to percussion

Allergy to any of the drugs or anesthetic solution

Pregnancy or systemic illness

Failure of local anesthesia on first attempt

Patients not providing informed consent

Group Allocation

Patients will be randomly assigned to one of four groups:

Group Premedication Dosage (to be specified) I Placebo - II Ibuprofen [Standard dose] III Serratiopeptidase [Standard dose] IV Ibuprofen + Serratiopeptidase [Standard dose each]

Methodology

After obtaining informed consent, patients will receive their assigned premedication orally one hour prior to anesthesia. Pain levels will be assessed using the Verbal Numerical Scale (VNS) at the following stages:

Before premedication

After IANB administration

During access cavity preparation

At first file placement in the canal

The IANB will be performed using 2% lidocaine with 1:100,000 epinephrine (MEDICAINE - Korea). Lip numbness will confirm successful anesthesia. If lip numbness is absent, supplemental anesthesia will be administered. Only those achieving effective block (confirmed lip numbness) will proceed to treatment.

Pain perception will be categorized:

0-3: No or mild pain (Success)

4-10: Moderate to severe pain (Failure)

Rubber dam isolation and root canal procedures will be done by a single operator to ensure consistency. Data will be recorded in a coded proforma (Annexure B).

Data Collection Tools Patient data will be collected using a structured proforma (Annexure B).

Consent forms will be signed in both English and Urdu (Annexure A).

Data Analysis

Data will be analyzed using SPSS version 26:

Quantitative variables (age, weight): Mean ± Standard Deviation

Qualitative variables (gender, group success rates): Frequencies and Percentages

Statistical Tests:

Chi-square test for qualitative comparisons

Post hoc Bonferroni test for intergroup pain score comparisons

P-value ≤ 0.05 will be considered statistically significant

Ethical Considerations Approval will be obtained from the CPSP registration and research cell and the Institutional Review and Ethical Board.

All participants will be informed in detail and will sign a bilingual consent form.

Confidentiality of patient data will be strictly maintained.

Participation is voluntary, and patients may withdraw at any time.

Expected Outcome It is anticipated that patients receiving combined ibuprofen and serratiopeptidase premedication will show a higher success rate of IANB compared to those receiving either drug alone or placebo. If confirmed, this approach could improve anesthetic protocols in endodontic treatment of inflamed mandibular teeth.

• Inclusion criteria:

• Age group of subjects between 18-45 years
• Normal PDL appearance on IOPA
• No analgesics taken 12 hours prior to study
• Mandibular molars and premolars with deep carious lesion having sign and symptom of symptomatic irreversible pulpitis
• Exclusion criteria:

• Presence of periapical radiolucency on IOPA
• Teeth tender to percussion /traumatic teeth
• Allergy to medications/anesthetic solution
• Pregnant patient & systemic illness
• Patient in which local anesthesia is not effective in first attempt
• Patient not giving consent